A polymer compound can be designed so as to have various characteristics by selecting a monomer as a starting material and is employed in a wide variety of uses from industrial products to daily commodities. Use in a medical device is one of the uses of a polymer compound. A medical device is used in an environment where it comes into contact with a biogenic substance such as blood and a body tissue. If the surface of a medical device has a low affinity for a biogenic substance and a body tissue, a biological defense mechanism is activated to coagulate blood, with the result that a problem such as formation of thrombus occurs. Because of this, at least the surface of a medical device to be in contact with a biological component and a body tissue must be formed of a highly biocompatible material.
As the polymer compound to be used for a medical device, conventionally, 2-(methacryloyloxy)ethyl-2′-(trimethylammonio)ethyl phosphate (MPC) polymer (PMPC), a polymer having a betaine structure and a methoxyethyl acrylate polymer (PMEA), are known. However, PMPC and the polymer having a betaine structure are expensive and highly hygroscopic. Both have a problem in handling. PMEA cannot be said to have sufficient substrate adhesion.
Because of these problems, investigation has been further conducted on materials. Literatures disclose an article for a bio-related substance having a surface film, which is formed by bringing a coating composition for preventing adsorption of a bio-related substance, containing a copolymer obtained from a starting monomer containing two types of specific monomers, a cross-linking agent and a solvent, into contact with the surface, followed by heating (see, Patent Literature 1); an antithrombogenic material for medical equipment, formed of a graft copolymer obtained by graft polymerization of a specific radical polymerizable monomer to a thermoplastic elastomer (see, Patent Literature 2); a phosphorylcholine analogous group-containing polymer obtained from e.g., a phosphorylcholine analogous group-containing monomer as a starting material (see, Patent Literature 3); and a method for forming a layer of a therapeutic drug-containing composition bound to a specific copolymer, on therapeutic agent delivery medical equipment (see, Patent Literature 4). Other literatures also disclose various copolymers having a structure unit derived from glycerol mono(meth)acrylate (see, Patent Literatures 5 and 6).